A macro-micro collaborative networking system is a heterogeneous network (HetNet). The system can effectively resolve wireless network coverage problems, and can increase network throughput and improve user experience. In a cell covered by a macro base station, a deployed micro base station may be used to absorb hotspot services, supplement coverage of coverage holes, and so on. Digital baseband processing of the macro base station and the micro base station may be completed in the macro base station, that is, the macro base station includes a radio frequency transceiver module of the macro base station and a baseband processing module that provides a digital processing function for the macro base station and the micro base station, and the baseband processing module is mainly configured to process digital functions, for example, to execute the functions of channel coding and decoding and digital modulation and demodulation; and the micro base station site located at a remote end mainly includes a radio frequency transceiver module. Data transmission between a macro base station and a micro base station is one of key technologies of a macro-micro collaborative networking system.
An existing communication between a micro base station and a macro base station is mainly based on a common public radio interface (CPRI) protocol. An interface between a radio frequency transceiver module of the micro base station and a baseband processing unit is generally also a CPRI interface.
Currently, methods for transmitting data between a micro base station and a macro base station mainly include an optical fiber transmission method and a microwave transmission method. For the microwave transmission method, a data communication between the micro base station and a baseband processing unit of the macro base station is implemented by means of microwave transmission, and transmitted data is CPRI protocol data based on the CPRI protocol. This solution requires a very high data transmission bandwidth but a microwave transmission bandwidth is limited, which causes a great technical difficulty in meeting a bandwidth requirement for transmitting CPRI protocol data, and a high transmission cost.